<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2022\3\22 0022
 * Time: 17:25
 */

$a='2021-05-27 11:25:09';
$b='2021-09-06 09:31:46';
if($a>$b) {
    echo 111;
}else{
    echo 999;
}